The Antioxidant Status and Response to Therapy in Children With Soft Tissue Sarcomas and Neuroblastoma

Background. Antioxidant systems in cells maintain the proper homeostasis of reactive oxygen species, which at high concentrations can induce carcinogenesis. The aim of this study was to evaluate the serum levels of ischemia-modified albumin (IMA), erythrocyte superoxide dismulase (SOD), and glutathione peroxidase (GSH-Px) as markers for prognosis in children with neuroblastoma (NB) and soft tissue sarcomas (STS), two cancer types for which reliable prognostic factors are needed. Procedure. SOD, GSH-Px, and IMA were measured before and during responses to therapy assessment in 99 children with NB and STS and in 30 healthy controls. Results. There were no statistically significant differences in the erythrocyte SOD and GSH-Px activities between the patients with cancer and healthy controls. The levels of IMA in patients with STS and NB were found to be significantly higher than in the controls (P = 0.0013; P = 0.0066, and 0.0164, respectively). Decreased activities of SOD and GSH-Px were found in all patients with poor-responding (PRS) cancers and decreased SOD activity was found in patients with PRS NB. An increase in GSH-Px was observed in patients with good-responding (GR) NB. All patients with GR cancers demonstrated higher SOD and GSH-Px activities than patients with PRS cancers. Conclusions. While determining the levels of specific antioxidants as antioxidant-barrier parameters in children with cancer may be valuable in predicting therapeutic responses as well as outcomes, additional studies are required. Pediatr Blood Cancer 2011;57:561-568. (C) 2011 Wiley-Liss, Inc.